From 3d8fb3bceaa0451eecd3ce9005fdfa095e96673a Mon Sep 17 00:00:00 2001
From: Powei Feng <powei@google.com>
Date: Thu, 11 Sep 2025 09:48:50 -0700
Subject: [PATCH] vk: fix blitDEPRECATED implementation (#9201)

blitDEPRECATED can also be used in the context of a multisampled
texture resolve. Fix that case to use the resolve() path in the
VulkanBlitter.

Also fixed backend test BlitTest.ColorResolve to add the correct
usage bit (otherwise it'd have validation error).

FIXES=417229577
---
 filament/backend/src/vulkan/VulkanBlitter.cpp |  4 +---
 filament/backend/src/vulkan/VulkanDriver.cpp  | 11 ++++++++---
 filament/backend/test/test_Blit.cpp           | 11 ++++++-----
 3 files changed, 15 insertions(+), 11 deletions(-)

diff --git a/filament/backend/src/vulkan/VulkanBlitter.cpp b/filament/backend/src/vulkan/VulkanBlitter.cpp
index 79ec183941..a672fc2198 100644
--- a/filament/backend/src/vulkan/VulkanBlitter.cpp
+++ b/filament/backend/src/vulkan/VulkanBlitter.cpp
@@ -96,7 +96,6 @@ inline void resolveFast(VulkanCommandBuffer* commands, VkImageAspectFlags aspect
     VulkanLayout oldSrcLayout = src.getLayout();
     VulkanLayout oldDstLayout = dst.getLayout();
 
-    src.texture->transitionLayout(commands, srcRange, VulkanLayout::TRANSFER_SRC);
     dst.texture->transitionLayout(commands, dstRange, VulkanLayout::TRANSFER_DST);
 
     assert_invariant(
@@ -109,10 +108,9 @@ inline void resolveFast(VulkanCommandBuffer* commands, VkImageAspectFlags aspect
             .extent = { src.getExtent2D().width, src.getExtent2D().height, 1 },
     }};
     vkCmdResolveImage(cmdbuffer,
-            src.getImage(), fvkutils::getVkLayout(VulkanLayout::TRANSFER_SRC),
+            src.getImage(), fvkutils::getVkLayout(src.getLayout()),
             dst.getImage(), fvkutils::getVkLayout(VulkanLayout::TRANSFER_DST),
             1, resolveRegions);
-
     if (oldSrcLayout == VulkanLayout::UNDEFINED) {
         oldSrcLayout = src.texture->getDefaultLayout();
     }
diff --git a/filament/backend/src/vulkan/VulkanDriver.cpp b/filament/backend/src/vulkan/VulkanDriver.cpp
index 9bceec25f3..53abfa661d 100644
--- a/filament/backend/src/vulkan/VulkanDriver.cpp
+++ b/filament/backend/src/vulkan/VulkanDriver.cpp
@@ -1891,9 +1891,14 @@ void VulkanDriver::blitDEPRECATED(TargetBufferFlags buffers,
     VkOffset3D const srcOffsets[2] = { { srcLeft, srcTop, 0 }, { srcRight, srcBottom, 1 }};
     VkOffset3D const dstOffsets[2] = { { dstLeft, dstTop, 0 }, { dstRight, dstBottom, 1 }};
 
-    mBlitter.blit(vkfilter,
-            dstTarget->getColor0(), dstOffsets,
-            srcTarget->getColor0(), srcOffsets);
+    auto const& dstAttachment = dstTarget->getColor0();
+    auto const& srcAttachment = srcTarget->getColor0();
+
+    if (srcAttachment.texture->samples > 1) {
+        mBlitter.resolve(dstAttachment, srcAttachment);
+    } else {
+        mBlitter.blit(vkfilter, dstAttachment, dstOffsets, srcAttachment, srcOffsets);
+    }
 }
 
 void VulkanDriver::bindPipeline(PipelineState const& pipelineState) {
diff --git a/filament/backend/test/test_Blit.cpp b/filament/backend/test/test_Blit.cpp
index 6b58fbff84..636dc40f10 100644
--- a/filament/backend/test/test_Blit.cpp
+++ b/filament/backend/test/test_Blit.cpp
@@ -265,8 +265,6 @@ TEST_F(BlitTest, ColorMinify) {
 
 TEST_F(BlitTest, ColorResolve) {
     SKIP_IF(Backend::WEBGPU, "test cases fail in WebGPU, see b/424157731");
-    NONFATAL_FAIL_IF(SkipEnvironment(OperatingSystem::APPLE, Backend::VULKAN),
-            "Nothing is drawn, see b/417229577");
     auto& api = getDriverApi();
 
     constexpr int kSrcTexWidth = 256;
@@ -291,18 +289,21 @@ TEST_F(BlitTest, ColorResolve) {
             1, TextureUsage::COLOR_ATTACHMENT | TextureUsage::BLIT_SRC | TextureUsage::UPLOADABLE));
 
     // Create 1-sample texture.
+    // Note that BLIT_SRC usage is necessary because this texture will be read back.
     Handle<HwTexture> const dstColorTexture = mCleanup.add(api.createTexture(
             SamplerType::SAMPLER_2D, 1, kColorTexFormat, 1, kDstTexWidth, kDstTexHeight, 1,
-            TextureUsage::SAMPLEABLE | TextureUsage::COLOR_ATTACHMENT | TextureUsage::BLIT_DST));
+            TextureUsage::SAMPLEABLE | TextureUsage::COLOR_ATTACHMENT | TextureUsage::BLIT_DST |
+                    TextureUsage::BLIT_SRC));
+
 
     // Create a 4-sample render target with the 4-sample texture.
     Handle<HwRenderTarget> const srcRenderTarget = mCleanup.add(api.createRenderTarget(
-            TargetBufferFlags::COLOR, kSrcTexWidth, kSrcTexHeight, kSampleCount, 0,
+            TargetBufferFlags::COLOR, kSrcTexWidth, kSrcTexHeight, kSampleCount, 1,
             {{ srcColorTexture }}, {}, {}));
 
     // Create a 1-sample render target with the 1-sample texture.
     Handle<HwRenderTarget> const dstRenderTarget = mCleanup.add(api.createRenderTarget(
-            TargetBufferFlags::COLOR, kDstTexWidth, kDstTexHeight, 1, 0,
+            TargetBufferFlags::COLOR, kDstTexWidth, kDstTexHeight, 1, 1,
             {{ dstColorTexture }}, {}, {}));
 
     // Prep for rendering.